Figure 1. Overall structural comparisons of mFancI–FancD2 and hFANCI–FANCD2 bound to interstrand cross-linked DNA.

(A) The same domain architecture is shared by FANCI and FANCD2 and is shown schematically above. (B) Structure of mouse (m)FancI–FancD2 (PDB ID: 3S4W) where the ubiquitination sites, Lys⁵⁵⁹ residue of FANCD2 and Lys⁵²² residue of FANCI are shown in red sticks; FANCI phosphorylation sites are shown in blue sticks. Close-up view of FANCI phosphorylation sites, Ser⁵⁵⁵, Thr⁵⁵⁸ and Thr⁵⁶⁴ exposed on the heterodimer interface, and Ser⁵⁹⁵, Ser⁶¹⁶ and Ser⁶²⁸ residues buried in the complex. (C) Structure of human (h)FANCI–FANCD2 bound to interstrand cross-linked DNA (PDB ID: 6VAA). FANCD2 is colored in violet, FANCI in cyan and DNA in orange. Abbreviation: CTD, C-terminal domain.